Auto merge of #60714 - varkor:existential-global-lift-ice, r=oli-obk

Fix ICE with un-feature-gated existential type

Fixes https://github.com/rust-lang/rust/issues/60371.

r? @oli-obk
This commit is contained in:
bors 2019-05-11 12:25:11 +00:00
commit 5f1924c992
3 changed files with 69 additions and 18 deletions

View File

@ -611,26 +611,33 @@ impl<'cx, 'gcx, 'tcx> WritebackCx<'cx, 'gcx, 'tcx> {
}
}
let new = ty::ResolvedOpaqueTy {
concrete_type: definition_ty,
substs: self.tcx().lift_to_global(&opaque_defn.substs).unwrap(),
};
if let Some(substs) = self.tcx().lift_to_global(&opaque_defn.substs) {
let new = ty::ResolvedOpaqueTy {
concrete_type: definition_ty,
substs,
};
let old = self.tables
.concrete_existential_types
.insert(def_id, new);
if let Some(old) = old {
if old.concrete_type != definition_ty || old.substs != opaque_defn.substs {
span_bug!(
span,
"visit_opaque_types tried to write \
different types for the same existential type: {:?}, {:?}, {:?}, {:?}",
def_id,
definition_ty,
opaque_defn,
old,
);
let old = self.tables
.concrete_existential_types
.insert(def_id, new);
if let Some(old) = old {
if old.concrete_type != definition_ty || old.substs != opaque_defn.substs {
span_bug!(
span,
"visit_opaque_types tried to write \
different types for the same existential type: {:?}, {:?}, {:?}, {:?}",
def_id,
definition_ty,
opaque_defn,
old,
);
}
}
} else {
self.tcx().sess.delay_span_bug(
span,
"cannot lift `opaque_defn` substs to global type context",
);
}
}
}

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@ -0,0 +1,15 @@
trait Bug {
type Item: Bug;
const FUN: fn() -> Self::Item;
}
impl Bug for &() {
existential type Item: Bug; //~ ERROR existential types are unstable
//~^ ERROR the trait bound `(): Bug` is not satisfied
//~^^ ERROR could not find defining uses
const FUN: fn() -> Self::Item = || ();
}
fn main() {}

View File

@ -0,0 +1,29 @@
error[E0658]: existential types are unstable
--> $DIR/issue-60371.rs:8:5
|
LL | existential type Item: Bug;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: for more information, see https://github.com/rust-lang/rust/issues/34511
= help: add #![feature(existential_type)] to the crate attributes to enable
error[E0277]: the trait bound `(): Bug` is not satisfied
--> $DIR/issue-60371.rs:8:5
|
LL | existential type Item: Bug;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Bug` is not implemented for `()`
|
= help: the following implementations were found:
<&() as Bug>
= note: the return type of a function must have a statically known size
error: could not find defining uses
--> $DIR/issue-60371.rs:8:5
|
LL | existential type Item: Bug;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to 3 previous errors
Some errors have detailed explanations: E0277, E0658.
For more information about an error, try `rustc --explain E0277`.